Promising results for new cancer drug

A phase I clinical trial of a new cancer treatment has produced promising results

A phase I clinical trial of a new cancer treatment has produced promising results.

The study was conducted by scientists at The Institute of Cancer Research (ICR) and The Royal Marsden Hospital in conjunction with AstraZeneca.

The drug, olaparib, was used to treat patients with inherited forms of advanced breast, ovarian and prostate cancers caused by mutations on the BRCA1 and BRCA2 genes.

Olaparib works through a process of 'synthetic lethality' whereby the drug acts in combination with the patient's own molecular defect. The drug blocks an enzyme in the body called PARP and when the drug is applied to, in this case BRCA tumours, they are unable to repair their DNA and the cancerous cells die.

This new treatment targets the cancer cells but does not appear to damage healthy cells. It also has far fewer side effects than chemotherapy.

The results, published in The New England Journal of Medicine, show that tumours in more than half of the patients treated with olaparib either shrank or stabilised. After two years, one of the first patients treated with the drug is still in remission.

"This drug showed very impressive results in shrinking patients' tumours," said Dr Johann de Bono, one of the ICR scientists. "It's giving patients who have already tried many conventional treatments long periods of remission, free from the symptoms of cancer or major side effects."

Scientists believe that drugs such as olaparib will also be effective in other forms of cancer including some non-inherited breast and prostate cancers and up to half of the most common type of ovarian cancer.

The phase I trial involved 60 patients. It will need to pass phase II and III trials before it could become widely available.

Professor Alan Ashworth, director of the Breakthrough Breast Cancer Research Centre at the ICR, developed the approach of targeting defects in DNA repair in cancer. He said that he was delighted that the work carried out in the lab has been translated so quickly into potential benefit for patients.